Method of forming metallic bands



Nov. 27, 1945. F. J. BITTERMANN 2,389,758

METHOD OF FORMING METALLIC BANDS Filed Oct. 50, 1942 3 Sheets-Sheet 1 INV EN TOR.

F J. BITTERMANN METHOD OF FORMING METALLIC BANDS Nov. 27, 1945.

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Nov. 27, 1945. F. J. BMITTERMANN METHOD OF FORMING METALLIC BANDS Filed001:. so, 1942 Patented Nov. 27, 1945 METHOD OF FORMING METALLIC BANDSFerdinand J. Bittermann, Wheaton, 111., assignor to Victor Manufacturing& Gasket Company, Chicago, 111., a corporation of Illinois ApplicationOctober 30, 1942, Serial No. 463,991

2 Claims.

The present invention relates to metallic bands and especially to a bandadapted to be positioned in an annular groove in the circumference of aprojectile or shell. When so mounted the band has the dual purpose ofcausing the projectile or shell to rotate as it travels down the boreand the lands of the rifling cut into the relatively soft metal of theband, and to seal and prevent the explosion gases from escaping from thebore of the gun.

It is an important object of the present invention to provide a novelmethod and manner of producing such a band from a solid cylindricalblock of copper, gilding or other metal suitable for the purpose. Inthis novel method and manner of manufacture, no waste or scrap resultsas the density and volumetric content of the metal is not altered fromthe initial block to the final band, and the band or article so producedretains the initial strength and characteristics of the metal.

The present novel method comprises certain predetermined steps in whicha solid cylindrical metal structure or block through a sequence ofoperations, is transformed into a tubular band of predetermineddimensions. By this novel sequence of operations or steps, conicalpiercing and coining tools are forced successively into the oppositeends of the solid cylindrical. structure and byreason of the graduallyincreasing cross section of the tools, cause the material of theoriginal structure to be forced outwardly and downwardly until acylindrical band or tubular structure of desired dimensions is produced.The resultin article is of increased diameter and decreased heightproducing a continuous band having the desired characteristics anddimensions essential to a rotating shell band.

Further objects are to provide a construction of maximum simplicity,efficiency, economy and ease of assembly and operation, and such furtherobjects, advantages and capabilities as will later more fully appear andare inherently possessed thereby.

The invention further resides in the construction, combination andarrangement of parts illustrated in the accompanying drawings, and whilethere is shown therein a preferred embodiment, it is to be understoodthat the same is susceptible of modification and change, and comprehendsother details, arrangements of parts, features and constructions withoutdeparting from the spirit ofthe invention.

, In the drawings:

Figure l is a view in side elevation of a solid cylindrical structure orblock which is to ultimately form a rotating shell band.

Figure 2 is a composite view showing a piercing and coining tool and thesolid cylindrical structure or block before and after it is pierced bythis tool.

Figure 3 is a view similar to Figure 2, but showing the block orstructure reversed, the contour of the structure before it is pierced bythe tool being shown in full outline, and the contour after the piercingoperation, being shown in dotted outline.

Figures 4 to 21, inclusive, show diagrammatically the sequence ofoperations and the contour taken by the structure or block as it isbeing transformed into a band or tubular member, with the piercing andcoining tool forcing outwardly and downwardly the displaced metal toform a hollow structure of continuously increasing diameterbut of lessheight.

Figure 22 is a view in vertical cross section of they resulting bandformed by the novel method.

Figure 23 shows a section or block of copper or gilding metal shearedfrom a length of rod and in which the opposite faces may or may not beparallel.

Figur 24 shows diagrammatically the section or block placed in aflattening die and showing the conformation of the block after the diehas been compressed.

Figure 25 and Figure 26 are diagrammatic views showing succeedingoperations in piercing the opposite ends of the block.

Figure 2'7 shows the finished band.

Referring more particularly to the disclosure in Figures 1 to 22,inclusive, of the drawings, Figure I discloses a solid cylindricalstructure or block I of predetermined dimensions, density and volumetriccontent of metal suitable for forming an integral band. By the presentnovel method and manner of production, the dimensions of this structureor block are so altered and the metal content so arranged as to producea resulting end product in the shape of a band or tubular member 2having a final contour as shown in Figure 22', the resultant band havinga volumetric content of that of the initial structur or block, and thedensity substantially the same throughout the novel sequence of steps oroperations performed to produce the band 2.

Figure 2 shows the initial step or operation in which the solidcylindrical structure or block 1, shown in full lines, is placed on asupport below a conical piercing and coining tool 3 having a shoulder 4adapted to impinge against the upper surface 5 of the structure or blockwhen the tool has pierced the block to the desired extent, The dottedoutline shows the opening formed by the tool piercing the structure orblock and forcin outwardly and downwardly the displaced metal.

The next step in the sequence of operations is shown in Figure 3 inwhich the structure or block I is inverted to'expose the lower surfaceor opposite end 6 to the piercing and coining tool 3, which tool inpiercing the structure or block, forces the metal outwardly anddownwardly as shown in dotted outline in this figure, or as shown infull outline in Figure 4. The following sequence of operations arediagrammatically shown in Figures 4 to 21, inclusive, in which piercingand coining tools shown in broken outline and similar to the tool 3 butof gradually increasing cross section, are employed. It is to beunderstood that after each piercing in one direction, the structure isinverted and the tool is projected into and through the structure in thereverse direction from that; in the preceding operation.

The conical surface of the piercing and coining tools and their crosssection are so designed and determined that in each operation thematerial of the structure is forced outwardly and downwardly, andalthough it displaces or forces the metal outwardly and downwardly asthe tool is being forced down by the force or pressure applied thereto,it has been found that no waste or scrap results, but the volumetriccontent and density remain the same and that the resulting band 2retains the same cubic content of metal as that initially appearing inthe solid cylindrical structure or block I. For example, I have taken asolid cylindrical block I having a height of 2.29 inches and a diameterof 1.75 inches, and have formed by the present method a resulting band 2having the following dimensions: .97 inch high, .284 inch thick, with anouter diameter of 6.648 inches and an inner diameter of 6.080 inches,Each of these structures contains a volumetric content of 5.508 cubicinches of metal.

This example is given for illustrative purposes dimensions of the solidcylindrical structure or member from which the band is to be produced.

The final piercing and coining tool shown in Figure 21 is provided atits upper end with a cylindrical surface 1 of predetermined length todetermine the cylindrical surface 8 of the inner diameter of thecompleted band.

As shown in Figures 2 to 20, inclusive, the block I in its varioussequence of formations is mounted or positioned on a centering support9, those shown in Figures3 to 21, inclusive, having an opening [0 of asize approximating the size of opening in the adjacent surface of theblock being operated upon. The support shown in Figure 21 comprises acentering support H against which a sizing and finishing member l2 isadapted to engage, and these members in association with the surfaces I3and I4, and the cylindricalsurface l-of the tool, determine the finalsurfacing and polishing operation for the finished band. Preferably the.member H is adapted to be depressed a desired amount when the uppermember l2 engages therewith, and for such purpose, the member ll may bespringtensioned to return to the centering position shown; in Figure 21.This figure shows at the left hand side, the position of the tool andthe sizing and finishing members prior to the final operation, and atthe right hand side, the position of the band as the members are closed.It is to be noted that the band is forced outwardl and downwardly toassume the form of the finished band prior to the final coiningoperation,

By reason of the novel disclosed method in which the piercing andcoining tool forces the metal of the structure or block from which thefinal band is to be produced, outwardly and downwardly, no confiningwall or enclosure is provided for the structure and the metal is notcompressed, but is free to move in these directions. The degree ofmovement of material outwardly and downwardly is controlled by the angleof the entering piercing and coining tool, and occurs in suchrelationship that the density of the original material is not changed.

An important feature of this invention resides in the fact that thechange from the initial solid block to the final band is accomplishedwithout the removal or loss of any of the material of that block. Inorder to establish proper ductility, the metal is preferably annealed atthe desired stage or stages in the sequence of operation.

Figures 23 to 27, inclusive, disclose an altema form in which a block 15of greater length but of less diameter than that shown in Figure 1, mayby a similar sequence of operations as those shown in Figures 2 to 21,inclusive, be transformed into a band IS without the removal or loss ofmaterial. In this form of the invention, a rod of copper or gildingmetal stock may be cut or sheared into suitable lengths by a cut-offdie. If the sheared ends are not parallel, the block may then be placedin a flattening die consisting of upper and lower die members I! and I8,to assure parallel surfaces at the opposite ends I9 and of the block andto eliminate any distortion caused in shearing. This flattening andconforming operation initiates the downward and outward movement of themetal of the block.

Figure 25 shows the block in full outline as it is removed from theflattening die and placed on a centering support 2|, the dotted outlineshowing the initial piercing by a piercing and coining tool similar tothat shown in Figure 2, and the outward and downward movement of themetal caused by that piercing operation, Figure 26 shows the blockreversed for the second piercing and coining operation in a mannersimilar to Figure 3, with the centering support 2| provided with anopening 22. Subsequent, operations are similar to those shown in Figures4 to 21, inclusive.

Although the invention relates primarily to metallic bands and a methodand manner of producing them for use on shells or projectiles, its useis not limited thereto.

Having thus disclosed the invention, I claim:

1. The method of forming a metallic band for rotating shells orprojectiles from a solid cylindrical meta1 structure without theremovalor loss of metal, comprising the steps of forcinga coneshapedcoining and piercing tool into the central portion of the structure tocause an outward and downward pressure upon the material of thestructure without altering its density, reversing the position of thestructure so pierced, forcing the cone-shaped coining and piercing toolinto the opposite end of this structure, and successively forcing aseries of cone-shaped piercing and coining tools each of successivelygreater size into the opposite ends of the structurewith each tool insequence being forced'into one and then and forcing the cone-shapedcoining and piercing tool into the central portion of the opposite endof the structure, and successively forcing a piercing and coining toolof successively greater cross section into one and then the opposite endof the structure to thereby progressively increase its diameter anddecrease its depth to form a continuous band.

FERDINAND J. BITTERMANN.

